TV and music impresario Simon Cowell and author Sir Terry Pratchett have written to MPs and peers urging them to vote in favour of tougher internet piracy measures included in the digital economy bill as "a matter of urgency".

Cowell and Pratchett are among five signatories from across the UK's creative industries to a letter designed to put pressure on parliament to make the bill's anti-piracy proposals law.

The other signatories are Tim Bevan, co-chairman of Working Title Films, leading TV producer Stephen Garrett and Paul Greengrass, the British director of United 93 and the last two Bourne movies.

One of its key DEB clauses will give the courts the power to cut off consumers who download pirated music and films by forcing internet service providers to hand over details of persistent offenders.

The controversial proposal is fiercely opposed by ISPs including Carphone Warehouse, which argue it is not their job to police the internet, but the creative industries view it as crucial to the survival of the film, music, TV and publishing businesses.

In the letter, sent to parliamentarians today, Cowell and the other signatories say: "Britain is admired for its creativity and its sense of fair play."

The country's musicians, singers, actors, writers and directors, they say "contribute more than 7% to the UK economy".

"The digital economy bill.... will ensure that British creators, entertainment companies, and the 1.8 million people who work in and around the cultural sector are respected and rewarded in the future as they have been in the past."

"Digital entertainment services are really beginning to take off," the letter says, "but for these new business models to develop, it is critical that more is done to prevent the illegal services providing easy access to free content".

Greengrass is president of Directors UK, a campaigning body that also collects payments on behalf of TV and film directors. Garrett is executive chairman of Kudo Film and Television, which makes programmes including Spooks and Life on Mars.

There are concerns within the creative industries that the bill will not become law in the current session of parliament. A general election is widely expected to take place on 6 May and parliament will be dissolved before that.

Leading figures in the industry fear that if the measures designed to prevent consumers from illegally downloading content are not enacted now, the political momentum behind them will be lost for good.

There is no guarantee that the next government would reprise the legislation in its first few years, when more urgent manifesto commitments are likely to take precedence.

The Conservatives are opposed to some parts of the digital economy bill, including a provision to create independently financed news consortia, which will be given public money to make regional news programmes screened on ITV1.

Jeremy Hunt, the shadow culture secretary, has threatened to block the bill if that commitment is not removed. "This is a red line for us. We want this clause out of the bill", he said last month.

The opposition has the power to derail the legislation because of the crowded parliamentary timetable in the run-up to the election.

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